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递归下降分析法js版

article 2025/8/21 21:28:28

全部代码

<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8" /><meta http-equiv="X-UA-Compatible" content="IE=edge" /><meta name="viewport" content="width=device-width, initial-scale=1.0" /><title>Document</title>
</head>
<link href="https://unpkg.com/tailwindcss@^2/dist/tailwind.min.css" rel="stylesheet" />
<style>*:focus {outline: none;}
</style><body><div class="h-screen bg-gray-100 py-6 flex justify-center items-center w-full"><div class="w-full min-h-min md:w-1/2 md:h-1/2 m-9 relative"><div class="absolute inset-0 bg-gradient-to-r from-green-300 to-blue-300 shadow-lg transform md:-skew-y-6 sm:skew-y-0 sm:-rotate-6 sm:rounded-3xl rounded-md"></div><div class="p-8 relative min-h-min z-10 bg-white rounded-xl"><div class="uppercase text-black text-3xl md:text-base">INPUT expression</div><div class="mt-5"><input type="text" class="px-2 ring-2 py-3 md:py-0 rounded-md w-full md:w-1/2" id="inputExpress" /><input type="button" value="S t a r t" class="uppercase mt-6 md:mt-0 md:ml-3 px-3 md:py-1 py-2 w-full md:w-min rounded-md cursor-pointer bg-blue-400 text-white" id="inputInput" /></div><div class=""><div class="uppercase text-black text-3xl md:text-base mt-6">out result</div><textarea class="resize-none border ring-2 m-2 w-full h-36 rounded-md p-2 box-border" id="textareaInput"></textarea></div></div></div></div>
</body>
<script>let printf = () => {let inputText = document.getElementById('textareaInput')printf= {log: (str) => {inputText.value += str + '\n'},clear: () => {inputText.value = ''inputText.value = ''}}}function getResult(strExpression) {let isValid = true,nowI = 0E()return isValidfunction E() {printf.log('E=>TG')T()G()}function T() {printf.log('T=>FS')F()S()}function G() {printf.log('G=>ε')if (strExpression[nowI] == '+') {nowI++printf.log('G >+TG')T()G()} else if (strExpression[nowI] == '-') {nowI++printf.log('G >-TG')T()G()}}function F() {if (strExpression[nowI] == '(') {nowI++E()if (strExpression[nowI] == ')') {nowI++printf.log('F=>(E)')} else flag = false} else if (strExpression[nowI] == 'i') {printf.log('F=>i')nowI++} else isValid = false}function S() {printf.log('S=>ε')if (strExpression[nowI] == '*') {nowI++F()S()} else if (strExpression[nowI] == '/') {nowI++F()S()}}}window.onload = () => {let inputExpress = document.getElementById('inputExpress'),inputInput = document.getElementById('inputInput')printf()inputInput.onclick = () => {printf.clear()printf.log(getResult(inputExpress.value) ? 'Accepted' : 'error')}}
</script></html>